The first will give you the total number of milliseconds that have elapsed.

The second will give you the total elapsed in 5 second increments. Essentially, the timer runs on a delay of 5000 milliseconds, and fires the timer event at each tick. The event calls the doTimer function. The e.target.currentCount gives you the number of times the event has fired, which you multiply by the delay to get the total time passed.

The first is more versatile, and allows the time between to be variable, but doesn't allow you to control the amount of time between the start and the calculation.

The second is great where you want to have something happen every x milliseconds.